1. Field of Invention
This invention relates to microencapsulation of materials, particularly oxygen and/or water sensitive materials, which microcapsules reduce or inhibit oxygen and/or water permeation into the interior space to thereby protect the encapsulated materials.
2. Description of Related Art
In many industries, various ingredients are used that exhibit significant decrease or degradation in their desired properties due to oxidation and/or hydrolysis. For example, the food, pharmaceutical, nutraceutical, cosmetics, consumer products, personal care, agrochemical, and chemical industries utilize a significant number of substances that are prone to oxidation. As the substances oxidize, the desired properties of the substances can be decreased or degraded, or even eliminated, or the properties of the substance can be changed entirely to provide undesired properties. In these instances, oxidation protection is required in order to ensure that the substances provide their desired effects at the time of their ultimate use.
For example, the food industry is making increased use of unsaturated fatty acids in a variety of products. For example, unsaturated fatty acids such as eicosapentaneoic acid (EPA), docosahexaenoic acid (DHA), aracadonoic acid (ARA), and conjugated linoleic acid and linolenic acid (CLA) have found increasing use in recent years. However, these unsaturated fatty acids are susceptible to oxidation, which could render the acids unsuitable for their intended use. Other food ingredients, such as vitamins, nutritional supplements, minerals, herbal products, food additives, amino acids, and the like, including, for example, betacarotene, lutein, zeazanthin, iron salts, copper salts, selenium salts, flavonoids, coenzyme Q10, herbs, spices, and flavorants and extracts (such as allicin or garlic extract), are also susceptible to oxidation.
In a similar manner, numerous protein and peptide drugs and amino acid residues, especially sulfur-linked amino acid residues, require oxidative protection to retain their desired activity. This principle also applies to such additives as surfactants, enzymes, peroxides, and fragrances, typically used in such commercial products as antiperspirants, deodorants, toothpastes, and detergents.
In the chemical industry, numerous reactants and intermediaries are also subject to hydrolytic damage. For example, numerous catalysts such as Ziegler-Natta, Fischer-Tropsch catalysts, and the like are sensitive to hydrolysis and oxygen.
Despite the recognized problems of oxidative and hydrolytic damage to numerous chemical compounds and entities, the need continues to exist for effective means to counter the oxidation or hydrolytic process. The need thus exists in the art to provide effective protection for a wide range of materials, to avoid oxidation damage and hydrolytic degradation to preserve the desired positive properties of the materials.